植物多糖在食品乳状液中的应用研究进展

食品乳状液是热力学不稳定体系,由小油滴分散相和水连续相组成.植物多糖普遍存在于自然界植物体中,因其亲水性和高分子量而具有增稠保水性能,对乳状液有着乳化的作用.详细介绍了植物多糖在食品应用中的乳化特性、乳化稳定的机制及其应用研究进展.乳化剂是具有两性分子结构特点的表面活性成分,其通过吸附到液滴表面并降低在均质化期间的界面张力来促进乳液形成以实现不同程度的均匀性和稳定性.植物多糖表现出的亲水亲油特性有多方面的因素影响.一些研究者认为植物多糖的乳化特性和其所含有的蛋白质有关.还有一些研究者认为植物多糖的乳化特性与自身所具有的疏水基团与亲水基团有关.还介绍了几种目前学术界公认具有较好的乳化性能的植物多糖乳化剂.     

裂隙岩石疲劳损伤变形规律CT试验初探

基于对裂隙岩石的细观CT试验，对含有单一裂纹的贵溪红砂岩在单轴疲劳荷载作用下的损伤扩展机理和演化过程进行了初步的试验研究。结果表明，含有预制裂纹的红砂岩的损伤演化和裂纹的扩展受到预制裂纹的影响，破坏裂纹从预制裂纹尖端起裂，并且最终破坏发生于含有最大预制裂纹的层面。     

Application of FEM Analysis to Braced Excavation

It is becoming possible to do detailed numerical analyses for the various mechanical behavior of braced excavation by researching and developing the numerical analysis technique such as the finite element method (FEM). However, the mechanical behavior of braced excavation has not been clarified fully both in theory and in experience. Therefore, improving the prediction accuracy during the prior design is very important for making the observational method of braced excavation more effective. In this paper, FEM analyses were performed for a model of braced excavation by using Geotechnical Finite Element Elasto-plastic Analysis Software, GeoFEAS (2D). As the constitutive law of ground, MC-DP model, and Duncan-Chang model were applied. The results were compared and discussed with that of a site measurement, and the effects of the constitutive law of ground on the analyzed result were verified. For the difference between the results, the reason was investigated by the analyses adjusting the elastic modulus of ground, and the appropriate application of the constitutive law was researched.